1. Field of the Invention
The present invention relates to electronic packages including an electrical component connected to a substrate having a plurality of substantially vertical and horizontal signal wires distributed through the substrate, and more particularly, to an electronic package having an integrated circuit connected to a substrate having a plurality of substantially vertical and horizontal signal wires distributed through the substrate and defining multiple layers in the substrate terminating at a circuit board.
2. Description of Related Art
Current electronic packages may include multiple signal wires which define layers in a substrate The wiring layers within the substrate may be of varying widths and lengths. Each layer may offer specific wiring density and resistance attributes. Signal wires in a given layer may be manufactured with a low density and a low resistance by, for example, using large width wires. Further, signal wires may be manufactured having a high density and a high resistance by, for example, using small width wires. Generally, high density wiring allows fewer wiring layers, however, low resistance wiring results in better performance. Typically, about twelve to twenty layers of signal wires are in the substrate. Commonly, reference metal or reference material is also positioned in one or more layers in the substrate to provide current from a power supply outside the electronic package, and an electrical return path.
Typically, an electrical component, such as a die or integrated circuit is positioned on the package substrate. The integrated circuit has electrical contacts which contact the package substrate. Once positioned on the package substrate, the integrated circuit defines a die shadow on the package substrate generally equal to the perimeter of the die or integrated circuit. The electrical contacts may include, for example, solder balls. Thin signal wires may be used to enhance signal wire density in the package substrate proximate to the electrical contacts of the integrated circuit. The signal wires themselves can vary in thickness as they pass through the substrate.
Known in the art are multi-layered circuit boards having signal wiring conductors arranged on a first or second insulating layer, and signal wiring conductors arranged on a third or fourth insulating layer. The insulating layers are sequentially overlayed by arranging the signal wiring conductors on the same insulating layers substantially parallel to each other. Wiring conductors can also be arranged in parallel while interposing an insulating layer therebetween. The wiring on successive insulating layers may intersect at right angles using signal wires or vias. Ground and power wiring conductors are connected using conductors distributed through the insulating layers.
Other known devices include printed wiring boards including first and second overlapping boards. A conductive wiring pattern is formed on a portion of the first flexible board including an inspectional land used to inspect the conductive pattern on the flexible board. The first and second flexible boards overlap such that the conductive wiring pattern and the inspectional land do not overlap each other in a direction parallel to a plane which is parallel to the first and second flexible boards.
There are disadvantages of the known methods described herein for connecting integrated circuits or electrical components through the substrate to terminate at the circuit board or termination structure. The desire to increase the density of signal wires connected to the electrical connections of, for example, the integrated circuit leads to thinner signal wires, having undesirable resistance attributes. Thus, the known devices typically include thin or small width signal wires in congested areas resulting in undesirably high resistance in the signal wires in those areas in the package substrate. Also, other devices may provide a signal wire starting with a thin, narrow layer which may widen or increase in thickness or width. However, one of the disadvantages of this method is a low resulting characteristic impedance.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide an electronic packaging device having increased signal wire density with lower signal wire resistance.
It is another object of the present invention to provide an electronic packaging device which provides communicating signal wires of varying thicknesses and positioning in a substrate.
It is yet another object of the present invention to provide an electronic packaging device having multiple reference planes.
It is another object of the present invention to provide a method of electronic packaging having increased signal wire density with lower signal wire resistance.
It is yet another object of the present invention to provide a method of electronic packaging providing signal wires having multiple thicknesses.
It is a further object of the present invention to provide a method of electronic packaging having multiple reference planes.
An electronic package device connected to a power source which comprises an electrical component including a plurality of connection elements on a surface thereof. A substrate having top and bottom surfaces is positioned beneath the electrical component and adapted to receive the connection elements of the electrical component on the top surface thereof. The substrate defines a plurality of horizontal layers, and a plurality of substantially horizontal conductive signal wires traversing the substrate along the horizontal layers in the substrate such that a first horizontal signal wire travels along a first substantially horizontal layer. The first signal wire includes a first vertical thickness which may be less than about 150 microns, and a first resistance measurement. A second horizontal signal wire travels along a second horizontal layer positioned beneath the first horizontal layer. The second signal wire has a second vertical thickness greater than the first vertical thickness of the first horizontal signal wire, and may also be less than about 150 microns, and a second resistance being lower than the first resistance of the first horizontal signal wire. At least one substantially horizontal reference plane is within the substrate along one of the substantially horizontal layers. The reference plane includes a vertical thickness and the power source is connected to the horizontal reference plane. The device further includes a plurality of substantially vertical conductive vias having a specified diameter, and at least one of the conductive vias may communicate with a multiplicity of the horizontal signal wires. The plurality of substantially vertical vias may have a diameter being less than about 120 microns, and include a first vertical via traversing the first and second horizontal layers such that the first via connects to the connection element and connects to at least one of the horizontal signal wires. An insulated board having connection members is positioned beneath the substrate such that the vertical conductive vias terminate and connect to the connection members.
In a related aspect the first and second vertical thickness of the first and second horizontal signal wire are between about 1-150 microns.
In another related aspect the diameter of the vertical conductive vias are between about 3-120 microns.
In still another related aspect the plurality of reference planes include reference planes having different voltages from one another.
In yet another related aspect the reference planes each have a voltage and the reference planes having a substantially similar voltage are connected.
In another related aspect the horizontal signal wires are positioned between at least two of the reference planes such that the first signal wire is positioned between a first reference plane and a second reference plane. The first reference plane is positioned along the first layer and includes a first vertical thickness, and the second reference plane is positioned along the second layer and includes a second vertical thickness.
In yet another related aspect the substrate includes a plurality of reference planes such that the vertical thickness of the reference planes increases as the reference planes are nearer the bottom of the substrate.
In still another related aspect the plurality of the conductive signal wires alternate thicknesses such that the first signal wire including the first vertical thickness and the second signal wire including the second vertical thickness and a third horizontal signal wire traveling along a third substantially horizontal layer positioned beneath the second horizontal layer in the substrate includes a third vertical thickness substantially equal to the first vertical thickness and a fourth horizontal signal wire travels along a fourth substantially horizontal layer positioned beneath the third horizontal layer in the substrate and includes a fourth vertical thickness substantially equal to the second vertical thickness.
In another related aspect the substrate includes a plurality of the reference planes being coincident with the plurality of layers.
In another aspect of the present invention, an electronic package device connected to a power source comprises an integrated circuit including a plurality of connection elements on a surface thereof. A substrate has top and bottom surfaces being positioned beneath the integrated circuit and is adapted to receive the connection elements of the integrated circuit on the top surface thereof. The substrate defines a plurality of horizontal layers. A plurality of substantially horizontal conductive signal wires traversing the substrate along the horizontal layers in the substrate such that a first horizontal signal wire travels along a first substantially horizontal layer. The first signal wire includes a first vertical thickness of less than about 150 microns and a first resistance. A second horizontal signal wire travels along a second horizontal layer positioned beneath the first horizontal layer in the substrate. The second signal wire has a second vertical thickness being greater than the first vertical thickness of the first horizontal signal wire, and a second resistance is lower than the first resistance of the first signal wire. A plurality of reference planes are within the substrate along the substantially horizontal layers and include a vertical thickness, the horizontal signal wires are positioned between at least two of the reference planes such that the first signal wire is positioned between a first reference plane having a first vertical thickness, and a second reference plane having a second vertical thickness. The first reference plane is positioned along the first layer and the second reference plane is positioned along the second layer. At least one of the plurality of reference planes includes conductive metal for connecting to and receiving current from the power source. The device includes a plurality of substantially vertical conductive vias having a specified diameter of less than about 100 microns. The plurality of substantially vertical conductive vias include a first vertical via traversing the first and second horizontal layers such that the first vertical conductive via connects to the connection elements of the integrated circuit and connects with at least one of the horizontal signal wires. A circuit board has connection members and is positioned beneath the substrate such that the vertical conductive vias connect and terminate with the connection members of the circuit board.
In a related aspect the plurality of reference planes include different voltages from one another.
In another related aspect the reference planes each have a voltage value and the reference planes having a substantially similar voltage value are connected.
In still another related aspect at least one of the vertical vias communicates with a multiplicity of the horizontal signal wires.
In yet another aspect of the present invention, a method of electronic packaging comprises providing an integrated circuit having a plurality of connection elements positioned on a surface thereof. A substrate is provided and positioned beneath the integrated circuit and coupled to the connection elements of the integrated circuit. The substrate defines a plurality of horizontal layers. The method provides a plurality of substantially horizontal conductive signal wires along the horizontal layers in the substrate such that a first horizontal signal wire has a vertical thickness and a second horizontal signal wire has a vertical thickness being greater than the vertical thickness of the first signal line. A plurality of reference planes are provided within the substrate along the substantially horizontal layers and include a vertical thickness. At least one of the plurality of reference planes are connected to the power source wherein the reference plane includes conductive metal for receiving current from the power source. A plurality of substantially vertical conductive vias are provided having a specified diameter. The plurality of substantially vertical conductive vias include a first vertical via traversing the first and second horizontal layers such that the first vertical conductive via connects to the connection elements of the integrated circuit and connects with at least one of the horizontal signal wires. A circuit board having connection members is positioned beneath the substrate such that the vertical conductive vias connect and terminate to the connection members of the circuit board. The plurality of vias are connected to at least one of the horizontal signal wires including a first via traversing the first and second horizontal layers connecting to the connection element and connecting to the first horizontal signal wire.
In a related aspect the reference planes each have a voltage value and the reference planes having a substantially similar voltage value are connected.
In another related aspect, after the step of providing a plurality of substantially horizontal reference planes, horizontal signal wires are positioned between at least two of the plurality of reference planes such that the first signal wire is positioned between a first reference plane having a first vertical thickness and a second reference plane having a second vertical thickness. The first reference plane is positioned along the first layer and the second reference plane is positioned along the second layer.
In yet another related aspect, the plurality of reference planes include different voltages from one another.